Researchers asked 263 people ages 19 to 37 how much they regretted either engaging in or passing up a recent casual sex experience. About 35 per cent of women surveyed expressed regret, compared to just 20 per cent of men. Plus, only 30 per cent of women said they were happy with their most recent one-night stand, while around 50 per cent of men said the same.

So it’s not really a surprise that women were more likely to be pleased with passing on no-strings-attached sex: 80 per cent said they were glad they declined a recent chance of casual sex. That’s nearly double the amount of men who said the same. (In fact, 30 percent of men regretted not getting frisky when they were given the chance.)

Women did worry more about pregnancy, sexually transmitted infections, and loss of reputation associated with casual sex, but those factors don’t account for the sex differences when it came to post-sex regret. Even the difference in sexual satisfaction didn’t seem to explain the disparity.

Instead, researchers suggested that it comes down to fundamental differences that tie into evolutionary psychology. Basically, women may be more wired to see sex as a way to have children with a supportive partner. A short-term rendezvous wouldn’t provide that for them. But for men, the results of short-term sex wouldn’t be so problematic - so they look for casual opportunities more than women do.